二滩水电站PSS对抑制系统低频振荡的作用

二滩电站首台机组发电时通过长６２２ｋｍ的一回５００ＫＶ的输电线路送电，此时等值于１同组与无穷大电力系统相连，呈弱联系，根据电力系统稳定性的要求，其励在系统联合会了ＰＳＳ系统。设ＰＳＳ的目的是当系统出现扰动时为发电机转子转速摇摆提供正阻尼，以增强与电力系统的联系，ＰＳＳ能在系统突然施加一个干扰，如线路退出运行或系统联系较弱和稳定裕度不够时，起到重要作用。二滩机组ＰＳＳ增益设定是根据现场试验进行调整，

The inhibition function of PSS on the low-frequency system oscillation in Ertan Hydro Station

The electricity produced by the first genera bition, ting unit of Ertan Hydro Station is delivered by a loop of 500 kV transmission line with the length of 622 km, which is equivalent to the connection of a generating unit and a infinitely great power system and is a poor connection. According to the requirements of the stability of power system, its excitation system adds the PSS in order to provide positive damping for the runner of generator to enhance the connection of generating unit and power system when the system is disturbed. The PSS can play an important role in the system when a disturbance is suddenly occurred or the system connection is poor and its stability allowance is inadequate. This paper describes, with emphasis, the field adjustment and low frequency oscillation analysis of PSS in combination with the actual conditions of the first phase project of Ertan Hydro Station. The gain value of the PSS for the generating unit of Ertan Hydro Station is adjusted on the basis of the field test, which has achieved good damping effectiveness. The practice showed that the addition of PSS to the generating unit is a economic and effective way for enhancing system stability and increasing power transmission capacity. With the full operation of six generating units and three loops of 500 kV line, the PSS and its parameters will be adjusted and re checked.